Perceiving emotions in the eyes: The biasing role of a fearful mouth.

The role of the eye region in interpersonal communication and emotional recognition is widely acknowledged. However, the influence of mouth expression on perceiving and recognizing genuine emotions in the eye region, especially with limited attentional resources, remains unclear. Thirty-four participants in this study completed a dual-target rapid serial visual presentation (RSVP) task while their event-related potential (ERP) data were simultaneously recorded. They were instructed to identify the type of houses and the emotional expression displayed in the eye region. The first target (T1) consisted of three upright houses, and the second target (T2) included fearful and neutral normal faces, mouth-scrambled faces, as well as composite faces (fearful eye + neutral mouth, neutral eye + fearful mouth). A robust mass univariate statistics approach was utilized to analyze the EEG data. Behaviorally, the presence of a fearful mouth facilitated recognition of the fearful eye region but hindered recognition of the neutral eye region compared to a neutral mouth. The ERP results showed that fearful expressions elicited larger N170, early posterior negativity (EPN), and P3 amplitudes relative to neutral expressions. The P1 amplitudes were increased, whereas the N170 and EPN amplitudes were reduced in response to normal and composite faces compared to mouth-scrambled faces. Collectively, these findings indicate that an unattended fearful mouth can capture covert attention and shape evaluation of eye expressions within a face, providing novel insights into the impact of visually salient mouth cues on cognitive processes involved in mind reading.